Improvement in screw-wrenches



" UNITED STATES PATENT OEEICE.

ANDREW Y. MCDONALD, OF DUBUQUE, IOWA.

IMPROVEMENT lN SCREW-WRENCHES.

Specification forming part of Letters Patent No. 38,316, dated April 28,1863; antedated April 8, 1863.

To all whom it may concern,.-

Be it known that I, ANDREW Y. MODON- ALD, of Dubuque, in the county ofDubuque and State of Iowa, have invented a new and ImprovedScrew-Wrench; and I do hereby declare that the following is a full,clear, and

exact description of the same, reference being is a front edge view ofthe same.

Similar letters of reference indicate corresponding parts in the twofigures.

The object of this invention is to obtain a screw-wrench which may bequickly applied to its work and adjusted with the greatest facility, soas to obtain a iirm hold on the nut, and at the same time be simple inconstruction, strong, durable, and capable of being manufactured at areasonable cost.

To this end the invention consists in the employment or use, with astationary jaw, of a sliding jaw applied to the shank of the wrench, inconnection with a spring, screw, and stop, the latter fitting in holesin the sha-nk, and all arranged as hereinafter shown and described.

To enable those skilled in the art to fully understand and construct myinvention, I will proceed to describe it.

A represents the shank of the wrench, which has a handle, B, fitted onone end of it, and a stationary jaw, O, at the opposite end. The shank Ais of square form, and upon it there is placed a sliding jaw, D, havinga spring, E, attached to its back end, which bears against the back ofthe shank A. In the under side of the sliding jaw D there is fitted inan internal or female screw, af, a male screw, F, which has a smallthumb-wheel, G, attached permanently to it, and beyond or below thethumb-wheel there is a smooth arbor, b, which is a portion of the rod onwhich the screw A is formed or cut. This arbor b passes through what maybe termed a stop, H, which is simply a square piece of metal having acylindrical projection, c, at its inner side, which fits in any of aseries of holes, d, in the shank A, as shown in Fig. 1, and thisprojection is retained in said holes by the spring E, as will be fullyunderstood by referring to Fig. 1. The opening or hole in the slidingjaw is beveled at the sides adjoining the front and back edges of theshank A, as shown at ax in Fig. 1, in order to admit of said jaw beingpressed forward at its lower part, to allow the projection c to bethrown free from the hole d in which it is fitted, and thereby permitthe jaw D to be wound on the shank. This may be accomplished by simplypressing the thumb on the back and lower part of said jaw. The jaw D,

i therefore, it will be seen, may be Very readily adjusted to the nut,and when brought in contact with it said jaw is relieved of the pressureof the thumb, and the spring E draws the projection c into the hole d inthe shank which is opposite to it. The operator then causes the slidingjaw to bind or press firmly against the nut by turning the screw E,through the medium of the thumbwheel G, the stop H serving as a bearingfor the screw. By this means the nut will be firmly clamped between thetwo jaws.

l would remark that the outer end of thc arbor Z is headed, or providedwith a button, bx, in order to prevent the stop being casually detachedfrom it.

By this invention I obtain a comparatively long movement or adjustmentof the jaw D, considerably longer than those of other Wrenches of thesame size. The jaw D may be quickly and readily applied to its work, andthe nut firmly grasped between the two jaws C D, and at the same time astrong, durable, and cheap wrench is obtained.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is-

The sliding jaw D, provided with the spring E, in combination with thestop H and screw F, the latter being fitted in an internal or femalescrew, a, in the jaw D, and the stop H provided with a projection, o, tofit in holes d in the shank A of the stationary jaw G, substantially asand for the purpose herein set forth.

A. Y. MCDONALD.

Witnesses:

JOHN MORRISON, Rom'. L. HILL.A

